local coroutine = coroutine
coco2 = coroutine.wrap(function (a,b)
    print("resume args:"..a..","..b)
    yreturn = coroutine.yield()
    print ("yreturn :"..yreturn)
end)
print(type(coco2))
coco2(0, 1)
coco2(21)
coco2(32)

--[[
    function
    resume args:0,1
    yreturn :21
    cannot resume dead coroutine
]]